code: def test_zero_ckpt():
      spawn(run_dist, 2)
  
file_path: colossalai/tests/test_zero/test_low_level/test_zero_ckpt.py
imports: import copy
  import pytest
  import torch
  import torch.nn
  from torch.nn.parallel import DistributedDataParallel
  from torch.testing import assert_close
  import colossalai
  from colossalai.testing import rerun_if_address_is_in_use, spawn
  from colossalai.testing.random import seed_all
  from colossalai.zero import LowLevelZeroOptimizer
label_desc: Use image node_id 4 for calling a global function with example usage: test_zero_ckpt() without return types